# How to count the number of each character from a text file (and the frequency of it)?

238 views (last 30 days)
Esther Kis on 28 Mar 2016
Commented: Amit Dubey on 2 Jun 2020
Create a function that takes a text file as input and returns a vector of size 26 with the frequency in percent of each character a, b, . . . z (not sensitive to case.) The frequency must be computed as the number of occurences divided by the total number of characters from a to z that occur, multiplied by one hundred. All other letters such as ø and ä as well as all symbols must be ignored.

Azzi Abdelmalek on 28 Mar 2016
s=importdata('file.txt')
str=upper(s(:))
str=[str{:}]
AZ='A':'Z'
long=sum(ismember(str,AZ));
for k=1:numel(AZ)
freq(k,1)=100*sum(ismember(str,AZ(k)))/long
end

Mounic Kumar on 25 Jun 2019
function charnum = char_counter(fname,A)
fid = fopen(fname,'rt');
if fid < 0
charnum = -1;
return
end
if fid >0 && ischar(A)
k=0;
end
charnum = k;
else
charnum = -1;
end
fclose(fid);

Amit Dubey on 15 May 2020
Edited: Amit Dubey on 2 Jun 2020
function n=char_counter(fname,character)
fid=fopen(fname,'rt');
if fid<0
n=-1;
return;
elseif ~ischar(character)
n=-1;
return;
end
end
c=0;
ol=fgets(fid);
while ischar(ol)
c=c+count(ol,character);
ol=fgets(fid);
end
n=c;
fclose(fid);
##### 2 CommentsShowHide 1 older comment
Amit Dubey on 2 Jun 2020
Thank you, just made required modifications

Priyamvada Shankar on 23 Mar 2019
Edited: Priyamvada Shankar on 23 Mar 2019
Please Help me with this ..function called char_counter that counts the number of a certain character in a text file. The function takes two input arguments, fname, a char vector of the filename and character, the char it counts in the file. The function returns charnum, the number of characters found. If the file is not found or character is not a valid char, the function return -1. As an example, consider the following run. The file "simple.txt" contains a single line: "This file should have exactly three a-s..."
Walter Roberson on 26 Mar 2019
note: your function returns -1 if the character is valid but not found. Your function should only be returning -1 if the file is not found or if the input is not a valid scalar character.

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